Electric cord plug



March 10, 1942. A, BROWNSTEIN 2,276,017

ELECTRIC CORD PLUG Filed oct. s, 19:59

Patented Mar. E05, 1 42 f ELECTRIC Arthur Brownstein, Bridgeport, Conn.,

I PLUG assignor to Colonial Company, Attleboro, Mass., a corporation oiode island Application ctober 6, 1939, Serial No. 298,229

3 Claims.

This invention relates to electric cord plugs, and though notlimitedthereto, is particularly suitable where the plug body is made in onepiece of somewhat elastic deformable material within which the contactprongs are embedded and interlocked.

One object of this invention is to provide such a plug wherein theprongs may be readily asy sembled in the body and when assembled areautomatically locked against removal.

A further object is to provide such a plug wherein the prongs canbereadily formed in a simple stamping operation and wherein the samestamping can be employed for each prong, the body being formed withright and left slots to receive these prongs. By this arrangement diesof but one type need be employed, and there is no possibility at anytime of there being a shortage of prongs for one set of slots and asurplus of prongs for the other set of slots.

These extensions form an obstruction in each of the slots 9, whichobstruction extends substantially half way across the'width of the slot.The forked branches 1 are of greater width'than the lateral dimensionsof the slots 9 and thus form at their forward ends shoulders 20,*,theseshoulders merging withthe back shoulders I6 of the projections I.

The prongs I2, as shown best in Figure 2, each comprise a metallic stripsubstantially rectangular in cross section and of a width equal to thatof the portions which project outwardly from A still further object isto provide such a plug in which the prongs may be formed of bar stool:vin strips of no greater width than that of the projecting portions ofthe prongs.

For a more complete understanding of this invention, reference may behad to the accompanying drawing in which Figurel is a perspective viewof a cord plug embodying the invention. l

Figure 2 is a perspective view showing a pair of prongs securedto thecord and ready for assembly with the plug body. Figure 3 is a sectionalFigure 1.

Figure 4 is a sectional view on line 4 5 of Figure 3.

Figures 5 and 6 are fragmentary sectional views similar to a portion ofFigure 4, but showing modified constructions.

Referring to the drawing, at I is shown a plug body which may be of softrubber or other suit- View on line 3 3 of able material. In one face itis provided with an opening 2 for receiving an electric -cord 3 havingthe cord conductors t of the outer face of the body, extended to form abifuroated portion 6 having thevbranches 'I and 9. Each of thesebranches leads to the rear end of a slot 9, the two slots 9 beingarranged in parallel relation and opening out through the face I of thebody I. Each slot or opening 9 which is intended to receive theconducting prong I2 is provided with extensions It integral with thebody portion I at one edge of the slot, each extension presenting frontand rear shoulders I and I6, as shown in Figure 4.

the opening 2 is and 5. Inwardly the body I U and engage within theslots of the outlet with which the plug will lbe engaged. A pair of suchprongs are employed for each plug, but they are formed exactly alike sothat only one set of dies are necessary in order to form the prongs forboth slots. Each prong is provided adjacent to its rear end withsuitable means for the attachment of one of the conductors d or 5 of thecord. As shown such means comprises a slot 2| cut in from one side edgeof the prong, forming a finger 22 at the rear end of each prong aboutwhich the conductor may be wrapped and secured as by soldering or 'othersuitable means as at 23. The particular manner yin which the conductorsare secured to the prongs is, however, not material to this invention.

One side edge of each prong is cut inwardly as at 25, and as shown forsubstantially half the Width of the prong, and is then cut rearwardly asat 25 toward the conductor-securing means to form a lip 26. This lip isstruck away from the plane of the side faces of the prong as shown, soas lto present a shoulder or abutment 2'! at one face of the prong andextending crosswise, which when the prongs have been drawn through theplug from its rear end through the opening 2, abuts againstl ltheshoulder 20 of the opening t, While the projection I4 snaps intoposition between the forward edge 24 and the lip 26, as shown best inFigure 4, so that the projection I4 is retained within the slotted sideportion of the prong. The cut edge 2,4 engaging the forward shoulder- Itprevents the prong from being pushed backwardly within the body whilethe engagement of the lip or abutment 26 against the rear shoulder I6and the shoulder 20 of the body, prevents the prong from being pulledout of the body when the body is pulled rearwardly to disengage theprongs from their mating outlet socket. It willbe noted. that the lipsor shoulders openings 9 for receiving the prongs be arranged rights andlefts, the projections I4 of the two slots being arranged on oppositesides of the slo s.

Where the body is formed of soft rubber the prongs assembled with theconductors, as shown in Figure 2, may be drawn forwardly throughthe pluginto their final positions of Figure 3, whereupon the rubber, revertingtowardA its undistorted condition from the distortion produced when theprongs are drawn through, closes in and firmly locks the prongs inproper position.

If desired, the forward cut 24 may be undercut laterally of the prong asshown in Figure 5 yto form engaging faces inclined inwardly andforwardly of the'prong as shown in Figure 5, this producing anadditional security to the bond, preventing rearward displacement of theprong relative to the body.

If desired, instead of having the shoulder 26 on the prong arranged atright angles to the length of the strip from which the prong is made, itmay be arranged at an angle to right angles, as shown in Figure 6 at 30.This provides for somewhat greater flexibility of the locking projection32 of the body so that it facilitates the seating of the prong therein.The forward end of the prong may be perforated as at 3 l or otherwiseformed to provide a latching effect when the prongs are inserted intothe mating outlet socket as is well known in` the art.`

with one of saidl forked extension shoulders, and a pair of prongs eachlying in one of said slots and having a side portion partly cut away toreceive one of said projections and engage on its front and rearshoulders, said cut away portion being struck laterally of the plane ofsaid prong and engaging the shoulder ofone of said forked extensions. A

2. A cord plug comprising a one piece resilient body having a pair ofprong-receiving slots extending inwardly from one face, a cord-receivingopening extending into said body from another face, said cord-receivingopening having a forked extension leading to said slots and presenting a`pair of shoulders, each of said slots having an integral projection atone edge forming front and rear shoulders, the rea'r shoulder mergingwith one of said forked extension shoulders and being inclined to theperpendicular to the adjat cent edge of the corresponding slot, and apair of prongs each lying in one of said slots and having a side portionpartly cut away to receive one of said projections and engage on itsfront and rear shoulders, said cut away portion being struck laterallyoi the plane of said prong and at an inclination to matingly engage theinclined shoulder of one of said forked extremities.

From the foregoing description of certain emi bodiments of thisinvention, it should be evident to those skilled in the art that variousother changes and modifications might be made without departing from thespirit or scope of this invention as defined by the appended claims.

I claim:

1. A cord plug comprising a one piece resilient body having a pair ofprong-receiving slots extending inwardly from one face, a cord-receivingopening extending into said body from another face, said cord-receivingopening having a. forked extension leading to said slots and presentinga pair of shoulders, each of said slots having an integral projection atone edge forming front and rear shoulders, the rear shoulder merging 3.A cord plug comprising a one piece resilient body having a pair ofprong-receiving slots extending inwardly from one face, a cord-receivingopening extending into said body from another face, said cord-receivingopening having a forked extension leading to said slots and presenting apair of shoulders, each of said slots having an integral projection atone edge forming front and rear shoulders, the rear shoulder mergingwith one of said forked extension shoulders,`one of said shoulders beinginclined to the perpendicular to the adjacent edge of the correspondingslot, and a pair of prongs each lying in one of said slots and having aside. portion partly cut away to receive one of said projections andengage on its front and rear shoulders, said cut away portion beingstruck laterally of the plane of said prong and engaging the shoulder ofone of said forked extensions.

ARTHUR BROWNSTEIN.

